Waterbeds are being purchased and used with increasing frequency. In the construction of a waterbed, a plastic bag of right parallelepiped configuration is filled with water. A person using the waterbed reclines upon an upwardly facing sleeping surface, and is buoyantly supported by the water contained within the plastic bag. As the weight of the body is supported by the waterbed, the water within the bag is displaced, and must be accommodated in such displacement by the plastic cover. Due to the displacement of the water from a central location in the waterbed at a time when a person sleeps or rests thereon, some portion of the plastic bag containing the water must be able to expand sufficiently to accommodate the displaced volume of water. Such expansion occurs, inter alia, at the corners of the waterbed, causing the corners to project slightly farther outwardly from the center of the waterbed than when the waterbed is not in use.
The total weight of the water contained in the plastic bag forming the principle component of a waterbed is quite large. In some cases, over 1,000 pounds of water is contained in the waterbed. This prevents the corners of the waterbed from being easily lifted when making up the bed by placing the conventional bed covers thereon. Thus, it is difficult to place a mattress cover on the waterbed by tucking portions of the cover in under the water-containing bag. It is also difficult, with contour sheets or a contoured or corner pocket-type mattress cover, to lift the corners of the waterbed adequately to permit the mattress cover or contoured sheets to be fitted thereto in conventional fashion.
The present invention provides a novel mattress cover for use on, and in combination with, a waterbed. The mattress cover of the invention accommodates expansion and contraction occurring at the corners of the waterbed without displacement or stressing of the mattress cover, and also permits the matress cover to be quickly and easily secured to the waterbed without the necessity of lifting the corners to place a mattress cover pocket there around, or to tuck edge portions of the mattress cover beneath the waterbed.
Broadly described, the waterbed mattress cover of the present invention comprises a large rectangular panel which is dimensioned to be longer and wider than the upwardly facing sleeping surface of the right parallelepiped waterbed. The mattress cover panel thus has skirts at the top and bottom (or head and foot), as well as at the sides of the panel, which overlap, and will hang down along the sides of the waterbed. At two or more corners of the mattress cover panel, notches are cut from the intersecting sides of the panel at the respective corner. Preferably, such notches are cut at all four corners of the mattress cover panel, with the notches being of rectangular configuration. Stated differently, the preferred form of the notches which are formed at the corners of the mattress cover panel in such that two cuts are made inwardly from the intersecting sides of the panel at right angles to each other, so that a rectangular opening notch or recess is formed at that corner.
At each of the corners of the mattress cover panel where one of the described notches is formed, an elastomeric retainer band is extended across the notch at a location relatively close to the side edges of the panel, and such retainer bands have their opposite ends secured to portions of the panel at opposite sides of the notches. The ends of the respective bands are secured to the panel fabric well inwardly from the cut lines which define opposite sides of the respective notch.
With the notches formed in the manner described and the elastomeric retainer bands secured across these notches, the mattress cover panel is then placed upon the waterbed so that it is superimposed on the upwardly facing sleeping surface of the waterbed. The corners of the panel are then arranged so that the opposed side edges of the notches which have been formed at at least two of the corners are placed in juxtaposition to each other as a result of the elastic retainer bands pulling these edges toward each other. The retainer bands, thus extended across the corner edges of the waterbed, apply tension to the overlapping side portions of the mattress cover panel to retain it alongside, and in close proximity to, the sides, head and foot of the waterbed.
This construction facilitates secure placement of the mattress cover on the waterbed without the necessity of lifting the heavy corners of the waterbed. Moreover, the elastic retainer bands accommodate expansion and contraction of the waterbed without displacement of the mattress cover, and without causing it to skew or become misaligned.
From the foregoing description of the present invention, it will be perceived that the mattress cover of the invention facilitates quick and easy installation on a waterbed, and assures that the cover will remain neatly in place on the waterbed over extended periods of usage.
An important object of the invention is to provide a form-fitting mattress cover for a waterbed which can be quickly placed in position without the necessity for lifting the corners of the waterbed.
A further object of the invention is to provide a mattress cover for a waterbed which remains in proper position, despite expansion and contraction of the waterbed at its corners.
Additional objects and advantages of the invention will become apparent as the following detailed description of preferred embodiments of the invention is read in conjunction with the accompanying drawings which illustrate such preferred embodiments.